The current common method of controlling the temperature of photonics assemblies, for example one or more photonics devices mounted in a circuit pack, is the use of thermoelectric modules (TE). These are very inefficient modes of thermal control. Photonic sub-assemblies typically operate at a fixed temperature but are placed within modules and on circuit packs where they can have a requirement as the lowest temperature component, which results in heat load being drawn into the package. Currently one solution uses a heat spreading material in conjunction with a thermoelectric module. The module is powered to maintain a set point temperature and localized heating methods are employed to control specific component or location temperatures. For optic components this involves the addition of localized heaters to bring the local component up from the ambient temperature set by the thermoelectric module. Due to the thermal conductivity of the materials used, thermal crosstalk becomes an issue, resulting in more power required to drop the bulk thermoelectric module temperature. Thermal crosstalk is where the temperature of one active component affects another one. Thermal crosstalk results in larger power consumption by the thermoelectric modules and laser heaters.
Electronics chips do not usually use TE cooling, since TE cooling is inefficient, and further with electronics chips the main issue is to extract a large amount of heat, rather than controlling chip temperature precisely. Common arrangements used for cooling electronics chips are the use of fluidic cooling and/or fan air cooling.